diff --git a/src/types.ts b/src/Seconds.ts
similarity index 100%
rename from src/types.ts
rename to src/Seconds.ts
diff --git a/src/ast.ts b/src/ast.ts
index a41f8de..9c57a16 100644
--- a/src/ast.ts
+++ b/src/ast.ts
@@ -1,5 +1,5 @@
 import { IntervalType } from "./parser/tokenizer";
-import { Seconds } from "./types";
+import { Seconds } from "./Seconds";
 
 export type Workout = {
   name: string;
diff --git a/src/detectRepeats.test.ts b/src/detectRepeats.test.ts
index 2c20e86..0ecd29a 100644
--- a/src/detectRepeats.test.ts
+++ b/src/detectRepeats.test.ts
@@ -1,6 +1,6 @@
 import { Interval } from "./ast";
 import { detectRepeats } from "./detectRepeats";
-import { Seconds } from "./types";
+import { Seconds } from "./Seconds";
 
 describe("detectRepeats()", () => {
   it("does nothing with empty array", () => {
diff --git a/src/detectRepeats.ts b/src/detectRepeats.ts
index 2e047cf..90d2fa8 100644
--- a/src/detectRepeats.ts
+++ b/src/detectRepeats.ts
@@ -1,6 +1,6 @@
 import { eqProps, flatten, zip } from "ramda";
 import { Interval, Comment } from "./ast";
-import { Seconds } from "./types";
+import { Seconds } from "./Seconds";
 
 export type RepeatedInterval = {
   type: "repeat";
diff --git a/src/parser/parser.ts b/src/parser/parser.ts
index 062e5ba..ae6d871 100644
--- a/src/parser/parser.ts
+++ b/src/parser/parser.ts
@@ -1,5 +1,5 @@
 import { Interval, Workout, Comment } from "../ast";
-import { Seconds } from "../types";
+import { Seconds } from "../Seconds";
 import { ParseError } from "./ParseError";
 import { SourceLocation, Token } from "./tokenizer";
 
diff --git a/src/stats/totalDuration.ts b/src/stats/totalDuration.ts
index 54c95b5..f901768 100644
--- a/src/stats/totalDuration.ts
+++ b/src/stats/totalDuration.ts
@@ -1,6 +1,6 @@
 import { map, sum } from "ramda";
 import { Interval } from "../ast";
-import { Seconds } from "../types";
+import { Seconds } from "../Seconds";
 
 export const totalDuration = (intervals: Interval[]): Seconds =>
   new Seconds(sum(map((interval) => interval.duration.value, intervals)));
diff --git a/src/stats/tss.ts b/src/stats/tss.ts
index 2f1fa99..d795855 100644
--- a/src/stats/tss.ts
+++ b/src/stats/tss.ts
@@ -1,5 +1,5 @@
 import { Interval } from "../ast";
-import { Seconds } from "../types";
+import { Seconds } from "../Seconds";
 
 // Training Stress Score formula from Training and Racing with a Power Meter:
 //
diff --git a/src/stats/tss2.ts b/src/stats/tss2.ts
index c4ec722..da0802b 100644
--- a/src/stats/tss2.ts
+++ b/src/stats/tss2.ts
@@ -1,4 +1,4 @@
-import { Seconds } from "../types";
+import { Seconds } from "../Seconds";
 
 // Training Stress Score formula from Training and Racing with a Power Meter:
 //